Radiant-energy-generating unit



Dec. 30, 1930. R. H. MAxsoN 1,785,439

RADIANT ENERGY GENERATING UNIT v Filed May 241, 192'? Patented Dec; 30, 193() UNITED STATES PATENT OFFICE ROLLAND H. MAXSON, 0F MILTON, WISCONSIN', ASSIGNOR TO THE BUBDICK CORPO- BATION, OF' MILTON, WISCONSIN, A. CORPORATION 0F DELAWARE RADIANT-ENEBGY-GENEBATING UNIT cause the same to glow. It has been the` Ypractice, to attach the resistance and its refractory envelope to a suitable support (often in the general form of a lamp-socket plug base) by a central metallic post. Ob-

jections to such construction are the relativeI expense and complication, loss of energy by heat conduction through the post and differences in the coeicients of expansion between the envelope, support and post.

One of the objects of my invention is to provide an improved radiant energy generating unit.

Another object is to provide a unit of the character described in which a novel means is employed for retaining the refractory element, which when in use becomes hot, upon its support of insulating material.

A further object is to provide a unit in which the refractory elementis so constructed as to preclude any possibility of breakage due to unequal expansion of the various cooperating supporting elements. A A further object is to-provide a unit of the character described which by its novel structure affords maximum energy radiating surface.

Another object is to provide a unit wherein energy losses by heat conduction are' very materially reduced.

A further object is to provide a-unit of the character described which is of particularly durable structure and which may be manufactured at relatively low cost.

Other objects and advantages will hereinafter appear.l

In the drawing:

1 is a sectional view of a completed 50 unit;

.unit during the vrocess of manufacture.

generatin unit can better be understood a descriptlon of the various steps in the manufacture' thereof.

The unit includes a porcelain base memberl, generally annular in form, having segmental rabbeted portions 2 at the rearward end of its bore 3. The forward or outer end of the base is provided with a shallow annular groove 4 concentric with and disposed at the mouth of the bore 3. This groove et is for the purpose of supporting a temporary cylindrical shell or mold 5, of paper or other suitable combustible material, which iscarried by the basey during the process of manufacture in the manner shown in Fig. 3.

temporary form or core 6,"of wood or other appropriate lcombustible material, is provided and has wound thereupon several turns of an electrical resistance heating coil 7,'the turns of which are separated from each other byA a combustible cord 8.

The core 6 has a passage 9 extending longitudinally therethrough, through which the outer terminal 10 of the electrical heating coil 7 is passed so as to extend to a point below the bottom of the core.

An annular block 11, of wood or similar combustible material, having a central b ore 12 for receiving the lower end of the core 6, serves to close the segmental rabbeted portions 2 of the core. This block 11 has an enlargement 13 of its bore 12 for receiving the base 1.

The block 11 is further provided with a passage 14 extending therethrough through which the opposite terminal 15 of the electrical heating coil 7 extends to a point below the block.

With the parts assembled as thus described The construction of the radiant energy Y and as clearly shown in Fig. 3, the next step in the construction of the unit is that of pouring between the shell 5 and the core 7 a mixture of finely ground carborundum and a binder. such as silicate of soda, in semi-fluid condition whichis caused to settle thoroughly 3 about the heating coil 7 and fill the annulai` space between the temporary core and outer shell. The partially constructed unit is then put through a drying and baking process during which the parts are heated toa temperature sufficient to 4thoroughly harden the carborundum and silicate so as to form a self-supporting and hard refractory envelope for the resistance wire heat coil and to entirely consume by combustion the core 6 and tbe'shell 5 as well as the block 11.

Thus far I have described that part of the unit to the left of the line 2-2 in Fig. 1.

'Ihe remaining portion of the unit consists in a sub-base member 16 of orcelain, secured to the base 1 by bolts 17 w ich pass through aligned holes 18 and'19 of the base members 1 and 16 res ectively. I

This su -base- 16 has as its rear or inner end a lstandard metallic screw-plug-shell 2O for reception in Athe standard screw plug receptacle.

The shell 2O is .connected to the terminal 15 of the electrical heating coil by one of a air of bolts 22 employed for securing the shell to the base.

The terminal 10 of the electrical heatin coil is secured to a bolt 23 which passes longitudinally through the inner wall 24 of the sub-base 16 and forms the centerplug-contact for connecting the heating coil to the center contact of a plug receptacle.

The unit is now in readiness for use. In operation the unit is disposed in the ordinary type plug receptacle by means of the threaded shell 2O thereof, and a suitable reflector may be provided for directing the rays to a predetermined area.

When current is supplied through the shell 20 and the central contact member 23, the electrical heating coil 7 becomes heated and imparts its heat by conduction to the refractory envelope 25.

When used as an infra-red therapeutic lamp, the refractory element is heated to and maintained at a temperature which causes it to glow with a dull red color. At this temperature the emission of infra-red rays from the unit is very intense because of the blackl color of the envelope.- 'T he ratio of con-, version of electrical energy into the desired radiant energy is high because there is small loss by heat conduction since the only heat conducting path from the heating coil and its I envelope is through the relatively small area of contact between the envelope and the por- .celain support.v I

Due to the novel manner in which the refractory member is interlocked with the base member 1, no additional support is necessary for the refractory member, and thus the member is relatively freefrom the possibility of l rupture from eirpansion, as is often the case l,ment supported on the support solely by in- 1n the present style of heat generators and the like in which an ,element of refractory invention, 'it is to be clearly understood that my invention is not limited to these details, but is capable of other adaptations and modifications within the scope of the intended claims.

Having thus described my invention,

. -what I claim is:

l. A radiant energy generating unit, comprising a supporting base member, a sub-base secured to said base member and adapted for partial reception within va receptacle support, a refractory element carried -by said base and interlocking with the base, and an electrical.

heating coil imbedded in the refractory 'element and having electrical connections terminating at the sub-base.

2. A radiant energy generating unit, comprising a supporting base member, a sub-base.

secured to said base member and adapted for partial reception within a receptacle support,

g a cylindrical refractory element supported upright on the base and interlocking -with the base, and an electrical heating coil imbedded in the refractory element and having elecrical connections terminating at the subase.

3.' A radiant energy generating unit, oomprising a supporting base member, a sub-base secured .tosaid base member and adapted for partial reception .within a4 receptacle support with a recess in its supporting surface, said recess being enlarged at its inner end, a refractory element supported upon said base member and having a portion thereof received within said recess, therebyvinterlock# ing the element with the base, and an electrical heating coil imbedded with said refractory material. and having its terminals extending to the sub-base.

l 4. A radiant energy generating unit, comprising a supporting base member, a sub-base secured to said base member and adapted for partial reception within a receptacle support with recesses in itsy supporting surface, said recesses being enlarged at their mner ends, a

refractory element supported upon said base member and having a portion thereof received within said recesses, thereby interlockin the element with the base, andl an electrical eating coil imbedded with said refractory material and having its terminals extending tp the,

Iterlockingwith the support, and an electrig iso element and having electrical connections terminating at the sub-base.

6. A radiant energy generating unit comprising a support with a recess in its supporting surface, a sub-base secured to said support and adapted for partial insertion within a receptacle support, said recess being enlarged at its inner end, a rigid refractory element mounted upon said support and having a portion thereof lying within said recess, thereby interlocking the element wlth the support, and an electrical heating coil imbedded with said refractory material and lgaving its terminals extending to the subase.

7. A radiant energy generating heating unit comprising a support, a sub-base secured to said support and adapted for partialreception within a receptacle support, a refractory element carried by said support and interlocking therewith to form the sole means of holding them'together, and an electrical heating coil imbedded in the refractory elernent and having connecting terminals there- 8. In a radiant energy generating unit, a refractory element for emitting radiant energy, a heating coil embedded therein, and al base for said element having a flan e extending inwardly and interlocking with a 'p0rtion of said refractory element and having substantially the same coefficient of heat expansion as the element.

9. In a radiant energy generating unit, a tubular refractory element having an integral end wall, a heating coil embedded in the tubular portion of said element, a base enclosing the end of the refractory element, radially extending interlocking flanges on said refractory element and on said base for positively preventing axial withdrawal of the refractory element and means carried by said base forlmaking electrical contact with the heating co1 l0. In a radiant energy generating unit, a hollow refractory element having an end Wall and side walls, a heating coil embedded in the side walls thereof, a hollow base for supporting said element, radially extending interlocking flanges on said refractory element and on said base for positively preventing axial withdrawal of the refractory element and means carried by said base for making electrical contact with the heating coil.

In witness whereof, I hereunto subscribe my name this 18th day of May, 1927.

ROLLAND H. MAXSON. 

